View Full Version : BHP calculations????
I have been doing some block 120 datalogging today on my car, and now have an excel spreadsheet giving me Nm torque at certain RPM's,
Can someone please tell me how to turn these figures into a graph of power, and also does anyone know how to calculate the BHP figures from them too?,
Or has anyone written or know of a little program that does it automatically!
cordobabrendy
08-02-2002, 18:16
mosser, bhp and torque figures dont necessarily run hand in hand , take the seat wrc cordoba evo 3, its got 300 bhp but 550 lb/f my car has around 150 bhp but it has 133lb/f torque standard. you wwould need more fugures to do it accurately..................im telling you this and you probably know more about it than me!!! hehehe ;)
ibizacupra
08-02-2002, 19:16
Originally posted by Mosser
I have been doing some block 120 datalogging today on my car, and now have an excel spreadsheet giving me Nm torque at certain RPM's,
Can someone please tell me how to turn these figures into a graph of power, and also does anyone know how to calculate the BHP figures from them too?,
Or has anyone written or know of a little program that does it automatically!
Here you go Mosser.
http://www.badger-5.go-plus.net/bin/power-torque-calculator.xls
Just download this and insert your own data into it and the graph should update.
regards
Bill
Cheers Bill, thats exactly what i was looking for !!!, only trouble is that my 3rd gear datalog is about twice as long as the length of your coulmns!!!, my engine datalog runs till 6900rpm but your chart was out of puff at 5300!!
You must know excel inside out to be able to do that!!
All i've got to do now is clean my air filter cos its probably full of leaves and seeds by now, and clean my spark plugs because they are building up little stalagmites across the gap and are completely black from my engine troubles!!,
Anyone know what the plug gap should be on our engines?
My wife is a programmer and has just extended your table and the graph for me Bill, Ta!
ibizacupra
08-02-2002, 21:01
Originally posted by Mosser
My wife is a programmer and has just extended your table and the graph for me Bill, Ta!
No problem.
Enjoy.
regards
Bill
im not sure but aren't the plug gaps set these days no more tapping them on the engine with feeler gauges:cheers:
They might be, if i cant find out the plug gap i will just clean them
Originally posted by cordobabrendy
mosser, bhp and torque figures dont necessarily run hand in hand
Brendy ~ they certainly do bud!
Simple calculation:-
Power = [ (torquexrpm) / 5252 ]
If you know the torque & rpm you can work out the power at that engine speed ~ simple.
Oh yeah ~ read this! :)
http://www.seatcupra.net/power.shtm
Tony_Essex
11-02-2002, 16:48
Just thought I'd mention...don't forget the units, Broadly speaking Power = Torque x RPM, however the conversion factor (5252 shown in previous message) is dependent on the units you are using for Power (could be BHP or KW) and Torque( lbft or Nm).
(sorry used to be a mechanical engineer so get a bit stroppy over units)
btw handy spreadsheet thingy
cordobabrendy
11-02-2002, 18:51
i getcha, i was thinking that because my car has 150bhp and 133lb/f then a car with twice the bhp would have 266lb/f, then i saw the spec for the evo 3 wrc cordoba, it has 300bhp but 550lb/f approx, so this is why it threw me a bit!!!
now i understand!!!!
Impossible
19-02-2002, 20:33
Mosser!! Don't touch the plugs... you most probaly already done it.
They are Titumin ( not sure how you spell it) coated, if you rub them with a scotch pad or simallar, you remove the coating and they breck down very easy, best leave them alone.
Mic
Brushed them with a brass plug cleaning brush, then set all the gaps the same!, too late!!,
Any ideas on the problem i have posted on the upsolute forum mic?
ibizacupra
19-02-2002, 21:00
Originally posted by Tony_Essex
Just thought I'd mention...don't forget the units, Broadly speaking Power = Torque x RPM, however the conversion factor (5252 shown in previous message) is dependent on the units you are using for Power (could be BHP or KW) and Torque( lbft or Nm).
(sorry used to be a mechanical engineer so get a bit stroppy over units)
btw handy spreadsheet thingy
thats why I labelled the columns like I did.. Units need to be as specified, hence all the conversions on the sheet also for reference.
Bill
:)
Impossible
19-02-2002, 22:29
can't find your thread....mosser
Mic
I actually posted it on the bottom af someone elses thread!!, i have copied it into a new thread now on their forum, but it says...
I am using an AUQ engine in my Seat leon with VVT, but i have recently started to loose power, i dont think this is anything to do with the upsolute chip i am running, but i had an LPG coversion fitted that didnt work properly and had to be taken off, the place that did the conversion were running my turbo at 22psi for a few hundered miles, but now it has all been taken off i am having problems with the boost creeping up slowly over time, it is currently spiking to 22psi without the bleed valve that the LPG place fitted (now removed) and seems to be creeping up by about 1psi per month, the strange thing about it is that vag-com logging is showing that the ecu is actually requesting this amount of boost!!, my idle vacuum is around -20psi, which i believe is higher than normal chipped leons (-12psi),
Can anyone suggest what i should check?, or what the fault might be?,
I have vag-com and some data logs of various blocks if anyone is interested? and i can log additional blocks if needed